High Intensity Interval Training & Fat Loss

High Intensity Interval Training (HIIT) And Fat Loss

This article will discuss the benefits of HIIT for natural bodybuilders who are looking to shed excess fat, or just improve the efficiency of their cardiovascular (CV) system. It will discuss different energy systems and the benefit of HIIT in terms of calorie expenditure and fat loss.

As the name suggests HIIT is a training system that uses high intensity exercise at certain intervals, interspersed with much lower intensity.

An example of this would be: 15-second sprint followed by a 1-minute walk. Then repeat.

Key HIIT facts

HIIT is very hard to perform, as it requires us to push our body as hard as we can. Therefore HIIT workouts are usually quite short (for example 10 minutes). Obviously this doesn’t include a warm-up, which is essential and a warm-down.

HIIT can be performed on most CV exercises, for example running, cycling, rowing and swimming.

HIIT is a cardiovascular training system. It is mainly used in bodybuilding for losing fat through calorie expenditure and improving our VO2 Max.

Aerobic and Anaerobic exercise

Aerobic literally means ‘with oxygen’. In terms or exercise this means that our body uses oxygen in its metabolic process (energy).

Anaerobic is the opposite; it means without oxygen. The energy system used does not require oxygen for energy, but because of this it can only produce energy for a limited period.

These two main energy-generating systems have very different uses and produce very different results within the body.

Anaerobic is used when we are at maximal output for example sprinting or lifting heavy weights. Anaerobic exercise uses two energy systems, firstly the ATP system, which uses creatine phosphate as an energy source. This energy system is however very limited and produces waste products such as ADP (bodybuilders take creatine monohydrate to increase the amount of time this energy system can be used for to increase intensity during weight lifting).

Secondly is glycolysis where the body uses muscle glycogen for energy. Again this can only be used for a limited time.

Aerobic exercise uses oxygen to release energy and is the system we use most on a daily basis. It is used when we walk, or when we are sitting down. This energy system actually oxidises fat for energy and burns more fat than the anaerobic system for example a mile walk burns more fat than a mile jog. Does this mean it is the best for weight and fat loss? Simple answer no.

Losing weight is a very simple formula. We only use so many calories during a day. If we eat too many we must store them (put weight on). If we eat less than we need the body uses its energy stores (we lose weight). Having said that the body needs a healthy balanced diet if it is to be healthy.

Does HIIT actually burn more fat than low intensity CV exercise?

The reason why people think low intensity (LI) aerobic exercise burns more fat than high intensity (HI) anaerobic exercise is because they don’t look at the big picture. During the exercise period LI does burn more fat than HI, but LI does not put much strain on our body and it therefore recovers very quickly, so overall calories burned is relatively low.

Conversely HI places great strain on the body and therefore uses many more overall calories over a 24-36 hour period as the body recovers from the strain it was placed under. It also raises our metabolism much higher than LI

Therefore overall high intensity exercise burns more overall calories than low intensity exercise, and as we know to lose weight we must burn more calories then we consume.

It is also important to compare natural fat loss techniques compared to the techniques used by bodybuilders using illegal substances. Steroids give a great deal of help when dieting as they are fantastic at preserving muscle mass. Therefore bodybuilders that use steroids can use low intensity exercise for long periods (up to 12 weeks). However natural bodybuilders cannot do this for such a long period, as they will undoubtedly lose muscle mass. Therefore using a training system such as HIIT can have great benefit for natural athletes as it works much quicker.

Conclusion

HIIT provides many benefits over low intensity cardio. It raises our metabolism and burns more overall calories. It also trains our high intensity anaerobic systems to be more efficient, which is great for weight lifters.

However HIIT is very demanding and nothing in bodybuilding is a miracle cure. Therefore just like everything in our exercise regime it should be used in conjunction with different cardio exercises so that the body isn’t over-trained.